impossible to compare operands of type NavBoolean with NavOption when rename a record

NavImpr

Hi,

I have an issue with an installation of Dynamics NAV 2013.
When I try to Rename an Item (record 27) I get the error "impossible to compare operands of type NavBoolean with NavOption ".
This error pop up both if I Rename the record from code or If I rename it in the client.
With the debugger I see that the code on the OnRename trigger of the record runs without issues, the error above arises subsequently (the exact point doesn't show up in the debugger).
Do you have any advice on what can I check?

Thanks.